* refact: Changes required for gorm v2
* refact: Add db.DB wrapper and refact all test fixtures to use it
Stop leaking the gorm abstraction within our unit tests.
* refact: Migrate direct calls to pq to pgx driver
The refactor will remove the remaining direct dependencies on
the pq driver which has been deprecated in favor of the pgx
driver.
It includes the addition of common.SqlOpen which is a wrapper around
sql.Open, which is needed to deal with the driver name changing from
"postgres" to "pgx" but in our code base the dialect and driver are
synonyms.
Create Schema Manager and propagate contexts into the DB calls downstream.
Add checks at controller startup and database init for correct schema version and schema migration dirty bit being set.